Water-permeable drum for the hydrodynamic needling textile webs and method of making the drum

ABSTRACT

A water-permeable drum assembly for the hydrodynamic needling of textile materials in order to reinforce and structure the textile materials or refine the surface thereof has an intrinsically stable sieve drum provided with apertures and an outer tubular sieve-type cloth made of intersecting wires and pulled across and fixed to an outer surface of the drum. The outer sieve-type cloth has a coating that stabilizes intersections of the wires.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of PCT applicationPCT/EP2004/050788, filed 13 May 2004, published 25 Nov. 2004 as WO2004/101873, and claiming the priority of German patent application10322052.6 itself filed 15 May 2003, whose entire disclosures areherewith incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a water-permeable drum assembly for thehydrodynamic needling of textile materials such as nonwovens, tissue,cloth, knitted fabrics or similar in order to reinforce and structuresaid textile materials and/or refine the surface thereof, consisting ofan intrinsically stable drum provided with apertures and a tubularsieve-type cloth or knitted fabric which is made of wires.

Such drums are known in the field of flow-through drying from GBM 1 886883. The design is advantageous because the textile material to betreated does not lie on the perforated drum which would result innonuniform flow through the material web and marking of the drumperforation on the textile material. If, on the other hand, a coarsesieve-type woven fabric is preferably located first on the drum and thena finer fabric on which the textile material then comes to rest, thetreatment medium can treat the textile material uniformly over thesurface. For hydrodynamic needling it has also been considered that thecoarse sieve-type cloth, that is the under-covering, is replaced bystrips arranged closely adjacent to one another, for which purposereference is made to U.S. Pat. No. 6,055,710.

Practice has shown that creases form over the surface of the sieve-typecloth or knitted fabric. Creases form in the sieve-type cloth even whenthe sieve-type cloth consists of a diagonally woven or used tubularcloth which decreases in diameter under an axial tension produced duringassembly and thus comes to rest during assembly firmly and over theentire area on the supporting sieve drum or on the under-coating.Creases which are formed in practice, that is when the needling drum isused as the textile-material transporting drum, are especiallydisadvantageous. Nonuniform distortions which need to be avoided in anycase are then formed in the textile material as a result of thedistortions in the sieve-type cloth.

OBJECT OF THE INVENTION

It is the object of the invention to develop a drum assembly withsieve-type cloth or knitted fabric looped around said drum wherein thisformation of creases is made impossible.

SUMMARY OF THE INVENTION

Starting from the drum assembly of the type specified initially, theinvention consists in the fact that the sieve-type cloth or knittedfabric has a coating that stabilizes the intersections of the wires. Thesieve-type over-covering consists of metal wires which are interwoven orknitted together. Of necessity there is always the possibility ofmovement of the metal wires at the intersections of this over-covering.This is prevented by the coating. Thus, no more creases can form overthe surface of the drum.

It is especially advantageous if, as is known, the sieve-type cloth orknitted fabric is manufactured as a hose with a diagonal wire structure,it is then pulled over the sieve drum and brought to rest underlongitudinal tension so that it abuts against the jacket of the sievedrum over the entire area, or better, on a previously appliedunder-covering such as coarser sieve-type cloth. The over-coveringshould be joined to the two faces of the drum, which is usually effectedby soldering. The over-covering should then be coated, and specificallywith a coating that stabilizes the sieve-type cloth or knitted fabric atthe intersections of the wires.

In a simpler production process it is also possible to carry out thecoating before assembling the over-covering. The only important thingwith the desired drum is that the over-covering abuts against the sievedrum as firmly as possible over its entire area and the mobility of thewires is additionally eliminated. This is produced by the proposedcoating which can be provided by plastic or by a galvanically producedmetal coating, for example, by nickel plating.

BRIEF DESCRIPTION OF THE DRAWING

A drum of the type according to the invention and the possibleproduction process of the finally coated drum with over-covering isshown as an example in the drawings. In the figures:

FIG. 1 is a perspective view of a perforated sieve drum with asieve-type cloth pulled on under tension, which according to

FIG. 2 is completely dipped in a bath to produce a galvanically producedover-covering both over the ready-assembled sieve-type cloth and alsoover the drum, the same is disclosed by

FIG. 3 in the case of a perforated drum with a coarse sieve-type clothapplied previously to the drum as an under-covering for the additionallyfiner sieve-type cloth. This assembled drum, according to

FIG. 4 is dipped in the bath for galvanic coating with nickel.

FIG. 5 shows the production process for a sieve drum with coveredsieve-type cloth comprising partial steps a)-c) wherein the hose ofsieve-type cloth is nickel-plated, for example, without axial tensionand is then pulled over the drum and is soldered, clamped or similarlyattached; then

FIG. 6 shows the production process for a sieve drum with coveredsieve-type cloth comprising partial steps a)-c) wherein the hose ofsieve-type cloth is nickel-plated, for example, with axial tension butbefore assembly with the sieve drum and is then pulled over the drum andis soldered, clamped or similarly attached to the drum under axialtension, and then

FIG. 7 shows the production process for a sieve drum with coveredsieve-type cloth comprising partial steps a)-b) wherein the initiallyuntreated hose of sieve-type cloth having a diagonal structure is pulledover the sieve drum, then set under longitudinal tension and soldered,clamped or otherwise attached to the faces of the sieve drum. Only thenis the assembled drum dipped in the bath to nickel plate all the parts.

FIG. 8 further shows an enlarged view of a cross-section through thecoated sieve-type cloth or knitted fabric and

FIG. 9 shows the coated sieve-type cloth in a view similar to FIG. 8 butsaid cloth was coated after mounting on the sieve drum so that as aresult of the coating, a connection of the sieve-type cloth with thecircumferential surface of the sieve drum also exists.

SPECIFIC DESCRIPTION

In the above-cited U.S. Pat. No. 6,055,710 in FIG. 1 a device isdescribed where the textile material to acted upon by the water jets isguided between the endless sieves moving conically towards one anotherand thus the water jets initially pass through a sieve to bring aboutthe needling. Normally the textile material lies directly on the drum asis shown in FIG. 2 in this patent and the nozzle beam or beams with theemerging water jets are directly associated with the textile material.The water-permeable drum according to the design according to theinvention is applicable to both applications.

The outer surface of the perforated sieve drum 1 (the perforations 2 areshown in FIG. 2) serves as the element which bears the textile materialand transports it downstream. The perforations in the outer surface areused for radially directed removal of the water of the impinging waterjets, for which purpose the interior of the drum is under subatmosphericpressure. In order that this takes place uniformly over the surface ofthe textile material, a sieve-type cloth 3 is pulled over the drum 1,and as shown in FIGS. 1 and 2, the cloth can have a finer structure andbe soldered to the ends of the drum 1 under tension as indicated byarrows 4. The sieve-type cloth or knitted fabric 3 usually consists of ahose having a diagonal structure so that the hose is reduced in diameterunder the longitudinal tension produced during assembly and thus comesto rest on the drum 1 with its entire area.

Since the wire structure of the sieve-type cloth or knitted fabric 3also remains movable when the hose is under tension, the drum assembly1, 3 according to FIG. 2 is dipped in a bath 5 and is galvanicallycoated with nickel. The coating can also be accomplished differentlye.g., by zinc plating or using a plastic material which can be sprayedon. As a result, not only the wire structure of the sieve-type cloth 3is fixed permanently but also the sieve cloth 3 is connected with thedrum 1 over the entire area.

FIGS. 3 and 4 disclose the same except that a finer-structure tubularouter sieve-type cloth hose 6 is pulled over the coarser innersieve-type cloth 3 and is also brought to rest firmly on the drumassembly 1, 3 under tension 4 and is soldered to the ends of the drum.The coating is only then carried out according to FIG. 4.

A sieve drum with sieve-type cloth or knitted fabric looped around it,which is stabilized by a coating at the intersections of the wires, canbe produced in many ways. According to FIG. 5, a hose 6′ is suitablymade of a desired cloth or knitted fabric in a simple fashion accordingto a), then dipped in a galvanizing bath 5 according to b) and coated,and is then pushed over a relevant drum 1′ and soldered, clamped orotherwise attached to the face of the drum under tension as shown at 4″.

It is better if, as is shown in FIG. 6, the tubular sieve-type cloth 6′is gripped at the ends by an auxiliary structure 7, 8 and is stretchedto the correct dimension according to the arrow 4′. Then, as in FIG. 5b, the sieve-type cloth 6′, again without the drum but in the tensionedstate, is coated in the bath 5 and then pushed over the sieve drum 1′according to c) and soldered, clamped or otherwise attached to the facesof the drum under tension 4″.

The best solution is disclosed in FIG. 7. According to FIG. 7 a, thetubular sieve-type cloth 6″ having a diagonal structure is pushed overthe sieve drum 1, gripped at the ends by means of the auxiliarystructure and soldered or otherwise fixed to the ends of the drum 1under tension as indicated at 4″. This corresponds to the diagram inFIG. 1 or 3. The finally assembled drum 1 with the sieve-type cloth 6″resting thereon over the entire area and soldered thereto is theninserted in the dipping bath for coating as shown in FIG. 7 b in orderto obtain the desired drum with the coated sieve-type cloth 6″positioned firmly thereon as a result of the coating as shown in FIG. 9.

The stabilizing coating of the sieve-type cloth or knitted fabric isdeduced from FIGS. 8 and 9. By applying the coating agent to the wiregauze 6, 6′, 6″, a connection 10 of the superimposed wires 9 is achievedin any case at all intersections of the wires 9, which resembles awelding of the wires 9. The basically loose wire gauze is thusstabilized over its entire area. The diagram in FIG. 8 corresponds tothe method of producing the drum according to FIGS. 5 and 6. Accordingto FIG. 9, not only is the wire cloth stabilized but it is alsoconnected to the underlying surface by the coating 10′. The underlyingsurface can be the sieve drum 1 according to FIG. 1 or the cloth 3according to FIG. 3 which is likewise connected to the sieve drum 1 bythe coating 10′ after the production process according to FIG. 7.

1. A water-permeable drum assembly for the hydrodynamic needling oftextile materials in order to reinforce and structure said textilematerials or refine the surface thereof, the assembly comprising: anintrinsically stable sieve drum provided with apertures; and an outertubular sieve-type cloth made of intersecting wires and pulled acrossand fixed to an outer surface of the drum, the outer sieve-type clothhaving a coating that stabilizes intersections of the wires.
 2. The drumassembly according to claim 1, further comprising an inner tubularsieve-type cloth made of intersecting wires, underlying the outer cloth,and increasing a spacing between the outer surface of the sieve drum andthe outer sieve-type cloth, at least the outer sieve-type cloth havingthe coating that stabilizes the intersections of said wires of the outercloth.
 3. The drum assembly according to claim 1 wherein the outersieve-type cloth is applied to said sieve drum under tension, is fixedto ends of said drum, abuts closely against the outer surface of saidsieve drum over its entire area, and has the coating that stabilizes theintersections of said wires.
 4. The drum assembly according to claim 2wherein the inner cloth is applied to said sieve drum under tension, isfixed to ends of said drum, has a coating that stabilizes theintersections of said wires of the inner cloth and is additionallyconnected to the outer surface of the sieve drum by the coating.
 5. Thedrum assembly according to claim 1 wherein the coating is made ofplastic.
 6. The drum assembly according to claim 1 wherein the coatingconsists of metal.
 7. The drum assembly according to claim 6 wherein thecoating is produced galvanically.
 8. The drum assembly according toclaim 1 wherein the coating is produced by dipping treatment.
 9. Thedrum assembly according to claim 6 wherein the coating consists ofnickel.
 10. The drum assembly according to claim 6 wherein the coatingconsists of zinc.
 11. A method for manufacturing a water-permeable drumassembly comprising a sieve-type outer cloth made of intersecting wires,looped around a drum, and fixed to ends of said drum, the methodcomprising the steps of: providing the sieve-type cloth with a coatingthat stabilizes intersections of the wires; then cutting the clothtransversely to produce a section; joining the section to form a tube ofthe stabilized sieve-type cloth; and pulling the tube over the drum andfixing the tube to ends of the drum.
 12. A method for manufacturing awater-permeable drum assembly comprising a sieve-type cloth which ismade of intersecting wires, looped around a drum, and is fixed to endsof said drum, the method comprising the steps of: making an exactlyfitting hose of a labile sieve-type cloth; longitudinally tensioning thetube; providing the tube with a coating that stabilizes intersections ofthe wires; and pulling the tube over the sieve drum and connecting thetube to the ends of said drum.
 13. The method defined in claim 12,further comprising the steps prior to coating the tube and pulling thetube over the drum of: pulling a hose of a labile sieve-type cloth overthe drum; fixing the hose to ends of said drum under longitudinaltension and thereby bringing the hose into contact with an outer surfaceof the drum over the entire area thereof.
 14. The method defined inclaim 12, further comprising the step prior to coating the tube andpulling the tube over the drum of: pulling a hose made of a labilesieve-type cloth over the drum and thereby bringing the hose into directcontact with the outer surface of the under-covering over the entirearea, the stabilizing coating then being applied to the tube and to thehose.